Malay/Javanese origin. Bleeker (1850, 1858) indicates Ikan Wadder Bettah as the local name of Betta trifasciata Bleeker, 1849 (now Betta picta, Valenciennes, 1846) in the Ambarawa Javanese dialect. Ikan Wader is a common Javanese name for smaller freshwater fishes, especially cyprinids (already used in Old Javanese). See Blust, R. & Trussel, S. Austronesian Comparative Dictionary. Web Edition (https://www.trussel2.com/acd/).
Named for Apollo, the mythological Greek god of (among others) music, poetry, medicine and archery and which also refers to handsome young man; an allusion to the beautiful appearance of this species.